Job Accommodation Network, a government (DOL) sponsored website, is an excellent place to start assessing what accommodations an employee may need to perform his/her job.  The website breaks down the possible accommodations by each particular diagnosis.  It provides a separate web page for employers to review what their requirements may be regarding certain diagnoses.  

For some diagnoses, the appropriate accommodation cane be obvious.  Someone using a cane will have a clear need for stair handrails.  But, what about someone suffering from stress?  Or a worker suffering from bipolar disorder or sleep disorders?  JAN can help with all these diagnoses.  Any good accommodation will be based on medical opinion, but JAN may help the worker and the employer understand what questions to ask.